The present invention relates generally to synthetic fiber spinning apparatus. More specifically, the present invention relates to spinnerette assemblies employed to spin synthetic fibers.
The spinning of synthetic fibers is notoriously well known. In this regard, a melt or solution of fiber-forming polymeric material is extruded through extremely fine orifices formed in a spinnerette capillary die. The individual orifices may be virtually any geometric shape to form the desired cross-sectional fiber configuration to meet specific end-use applications.
In order to develop new or improved functional synthetic fiber cross-sections that can give desirable or enhanced fibers properties (such as superior soil hiding, comfort, stiffness, wear resistance, optical appearance, modification ratio and the like), spinneret capillary dies must be designed using a combination of mathematical modeling, engineering, practical experience and artistic ability. The final result in the design process is the need to fabricate many various capillary dies that are subjected to experimentation to determine the optimum fiber cross-section profile design.
There exists, however, real non-trivial problems associated with the design, testing and development of conventional spinnerette capillary dies. For example, the relatively large block capillary dies take a substantial time to produce and can be quite expensive as a result. As a result, there is little, if any, room for true trial and error development.
It would therefore be quite advantageous if spinnerette die capillaries could be provided which are relatively easily and economically fabricated to allow for a variety of spinnerette orifice design configurations to be tested during development. It is towards fulfilling such a need that the present invention is directed.
Broadly, the present invention is embodied in spinnerette assemblies for forming synthetic fibers whereby a relatively thin orifice plate is compressively sealed against a planar face of a mounting block. More specifically, the spinnerette assemblies of the present invention include a mounting block having a planar mounting face and a least one supply bore having a discharge opening at the mounting face. A planar orifice plate is positioned in contact with the mounting face of the mounting block and includes a capillary opening in fluid communication with the discharge opening of the supply bore. A series of attachments (preferably screws) circumferentially surround the capillary opening of the orifice plate so as to compressively rigidly fix the orifice plate to the mounting face of the mounting block and thereby seal the capillary opening against fluid leakage. Most preferably, the attachments (e.g., screws) are substantially equally circumferentially spaced apart from one another in surrounding relationship to the capillary opening so as to impart a symmetrical circumferential compressive sealing force therearound.
These and other aspects and advantages will become more apparent after careful consideration is given to the following detailed description of the preferred exemplary embodiments thereof.